Campbell Scientific CR9000X Measurement and Control System - Manual (Page 370)

Section 9. Program Control Instructions
Zero_mV/V
Variable
(array)
Zero calibration: The Variable or Variable array which will be populated with the zero
mV/V values. It must be dimensioned to the same size as the source MeasVar parameter. If
Zero_mV/V = NAN at the beginning of the Zeroing, it will be set to 0 during the calibration
process.
Shunt calibration: Zero can be entered for this parameter (not used).
Mode
Variable
This variable parameter stores an integer that indicates the current state of the calibration.
This value can be changed through automatic software or manually by the user using a
Keyboard display, with PC9000's Realtime Get/Set option, or through
LoggerNet's/RTDAQ's Connect Screen Numerical Display. The only values valid for
manual entry is 1 or 4.
Digit Edge
-1 Error in the Calibration setup
-2 Multiplier set to 0 or = NAN, measurement = NAN
-3 Reps is set to a value other than 1 or the size of the MeasureVar array
0 Calibration has not been done
1 Start Calibration. (For Shunt Cal, enter the gauge Resistance into the
KnownR parameter before setting to 1)
2 Computing (set by logger)
3 Only for Shunt. Ready to enter the shunt resistance into KnownR
4 Only for Shunt. Set by user after entering the shunt resistance into KnownR
5 Only for Two Point . Computing (set by logger).
6 Calibration is complete.
KnownR
Variable array Zero calibration: Zero (0) can be entered for the KnownR parameter (not used).
Shunt calibration: Variable array that holds the set point value(s) to be used in a shunt
calibration routine. This array must be dimensioned to the same size as the MeasVar. If Reps
is set to 1, then the element of the array used for the calibration is set by the Index parameter.
Before the Mode parameter is set to 1, the resistance, in ohms, of the strain gauge should be
loaded into the KnownR(Index) element of the array. After the logger takes the unshunted
measurement and changes the mode value to 3, the resistance of the shunt should be loaded
into the KnownR parameter.
Enter the resistance value as a positive number if shunting across:
The arm that holds strain gauge for Function 13
The arm that holds gauge that is parallel to +ε for Function 33
An arm that holds gauge that is parallel to +ε for Function 43
Enter the resistance value as a negative number if shunting across:
The arm that holds completion resistor for Function 13
The arm that holds gauge that is parallel to −ε for Function 33
An arm that holds gauge that is parallel to −ε for Function 43
After entering the value, the Mode value should be set to 4.
GF_Raw
Variable
(Array)
Zero calibration: Zero (0) can be entered for this parameter (not used).
Shunt calibration: When setting up a Shunt Calibration, the variable, or variable array,
which holds the raw gauge factor(s) for the strain gauges. It should be a different array than
that used for the adjusted gauge factors in the StrainCalc instruction, and the value(s) should
never be changed. This variable array must be dimension to the same size as the
MeasureVar.
Index
Constant or
Variable If Reps is set to the size of the MeasureVar, then Index must be set equal to 1 (complete
array will be calibrated starting with the first element). If Reps is set to 1, then Index
specifies which element of the MeasureVar array will be calibrated.
If Index is declared as a variable, it must be initialized to a non-zero value before a calibration
can be performed.
NumAvg
Var/Constant Used to specify the number of points (Scans) to average when performing a calibration.
uStrain
Var (array) Zero calibration: Variable array that is used to store the micro-strain reading result from the
StrainCalc instruction. Informs the Zero wizard of the variable array that is being zeroed.
Must be dimensioned to the size of the MeasVar.
Shunt calibration: Not required. Enter 0.
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